Study On Quality Change And Control Of Stored Grain Rice In North China

In order to study the rice qualities and control methods of the grain bin of North China,this article first studied the effect of different initial water and different storage temperature on the storage qualities of rice,and then studied the effects of different initial water and different storage temperature on the changes of the physical and chemical properties of rice,finally studied the changes of rice storage qualities and control methods of rice storage.The results of the study were as follows:1.The moisture content of different initial moisture conditions(moisture 12.4%,14.0%,12.4%)of rice was downward trend within 150 d of storage,the moisture content was fell 0.5%,1.9% and 0.5% respectively.The fatty acid value of rice increase gradually with the extension of storage time;The fatty acid value of initial moisture content of 12.4% and 12.4% of were not beyond the standard(25mgKOH/100g)of quality of rice in the 150 d of the storage period,the fatty acid value of high moisture content of paddy in a relatively short period of time had excessive 25mgKOH/100 g.High moisture content of rice color change was obvious,the L value decline rapidly.The sensory qualities and texture properties also declined with the increase of storage time,the low moisture content of rice quality decline was relatively slow and high moisture falling rapidly.2.The moisture content of rice was a downward trend within 150 d of storage,the moisture change was slow under the storage temperature 15?,two kinds of storage of rice moisture changes faster under the storage temperature 25? and 35?,and the moisture were fell by 0.5%,0.56% and 0.5% respectively.The rice of fatty acid value increased gradually under different storage temperature(15?,25? and 35?)with the extension of storage time,the rice of fatty acid value increased rapidly under the storage temperature 35 ?.The color of rice changed was obvious under the storage temperature 35 ?.The sensory qualities and texture properties also declined with the increase of storage time,the low low storage temperature of rice quality decline was relatively slow and high storage temperature falling rapidly.3.The indicators of reducing sugar,ECR,MDA,FN of the different initial moisture content conditions of rice were increases gradually as the extension of storage time;And the poor light penetration,POD,PPO were reduced gradually as the extension of storage time.The physical and chemical indicators to a great extent reflected the the difference of rice quality under different storage time.The changes of physical and chemical index of rice(initial moisture content 12.4%)were slow as the extension of storage time,the high initial moisture of rice should not be directly warehousing storage,and the moisture content need to down to an appropriate level under the conditions of storage.The changes of physical and chemical index of rice(storage temperature 15?)were slow as the extension of storage time,the low storage temperature to the benefit of storaging.4.The moisture of 9# grain bin and 13# grain bin were fell 0.5% and 0.7% respectively within the storage time of 30 d,the moisture falling slower in the two grain bins within the storage time of 90 d and maintained at a relatively stable level.The acid value of rice on the two grain bins had increased with the extension of storage time,but the senory quality had declined in a certain degree.Timely to mechanical ventilation increases the air flow in a grain bin and reduce the temperature and moisture content of rice,at the same time reduce the increase speed of the fatty acid value,delayed the decrease of the storage quality in a certain degree.The temperature of rice in 9# grain bin and 13# grain bin were controled at about 15?.Through the circulation fumigation and grain surface spraying treatments inhibit the growth of the pests effectively.